Description
free5GC is an open-source implementation of the 5G core network. Prior to 4.2.2, free5GC's SMF mounts the UPI management route group without inbound OAuth2 middleware. On top of that, the DELETE /upi/v1/upNodesLinks/{upNodeRef} handler unconditionally dereferences upNode.UPF after the type-guarded async release, even though AN-typed nodes are constructed without a UPF object. As a result, a single unauthenticated DELETE /upi/v1/upNodesLinks/gNB1 request crashes the handler with a nil-pointer panic AND mutates the in-memory user-plane topology before panicking (the UpNodeDelete(upNodeRef) line runs first). This is an unauthenticated, state-mutating panic-DoS sink that an off-path network attacker can trigger by name against any AN entry. This vulnerability is fixed in 4.2.2.
Affected products
free5gc: free5gc
References6
- github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-c… ExploitVendor Advisory
- github.com/free5gc/free5gc/security/advisories/GHSA-p9mg-74mg-c… ExploitVendor Advisory
- github.com/free5gc/smf/commit/b57bc48081c3d3a2f333d02eb78e4fd31… Patch
- github.com/free5gc/smf/pull/199 Issue TrackingPatch
- github.com/free5gc/free5gc/issues/905 ExploitIssue Tracking
- github.com/free5gc/free5gc/issues/905 ExploitIssue Tracking
Metrics
- CVSS 3.1
-
8.2
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H - EPSS — exploit probability
- 0% percentile: 26 · as of 14 November 2026
- CWE
- CWE-306CWE-476CWE-862
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